1.61 Ct. Yellow Sapphire from Ceylon (Sri Lanka)

This specimen is a transparent 1.61 carat round shape yellow sapphire, with measured dimensions of 7.11, 7.09, and 3.88 millimeters, presented in a classic faceted format. The cutting style is a mixed brilliant cut, executed to emphasize both color and return of light. The clarity grade is described as very very slightly included, evaluated at eye level, which indicates minimal visible material characteristics that do not detract from the overall face up appeal. Color intensity is intense, yielding a warm golden yellow that reads consistently across multiple viewing angles. The polish is excellent, producing crisp facet junctions and very clean facet planes. Enhancement is heat treated, a well established and stable technique in Ceylon sapphires to refine and stabilize hue and tone, and the documented origin is Ceylon, Sri Lanka, a source known for producing strongly colored and well crystalline corundum.

From a lapidary perspective the mixed brilliant execution on this round sapphire is calibrated to balance scintillation, color depth, and contrast patterning. A mixed brilliant typically uses a brilliant facet scheme on the crown to disperse and return light to the observer, while employing modified pavilion facets to control color saturation and back reflection. The cutter has targeted pavilion and crown angles appropriate for corundum, optimizing the critical angle for total internal reflection in a material with refractive index near 1.76 to 1.77. The measured depth of the stone yields a depth to average diameter ratio of approximately 54.7 percent, a geometry that supports even light return without excessive light leakage or an overly dark face up appearance. Facet symmetry and alignment are precise, which is evident in the uniformity of the star and lower girdle facets, and the excellent polish enhances the microfacet sharpness that produces crisp pinpoint scintillation.

Optical performance of this yellow sapphire should be compared to more common yellow gemstones with technical clarity. Compared to citrine and yellow topaz, which are quartz and aluminum silicate respectively, corundum exhibits a higher density and a greater refractive index, which translates to stronger contrast and more lively facet return. Quantitatively corundum has a refractive index around 1.76 to 1.77 and dispersion about 0.018, whereas common quartz has a lower refractive index and lower density, producing a less vivid face up brilliance. In contrast to diamond, which has a higher refractive index of 2.42 and dispersion near 0.044 producing exceptional fire, a well cut yellow sapphire offers a different, complementary optical signature. The sapphire delivers saturated face up color and a satin of warm fire within a field of intense yellow, rather than the high fire white flashes characteristic of diamond. Because the mixed brilliant cut here is tuned for corundum, the result is a lively interplay of contrast scintillation and strong color saturation, which often reads as greater perceived vitality in colored stones than the same size and weight in paler materials.

For buyers who value technical provenance and lapidary craft, this piece represents a refined balance of natural material quality and cutting expertise, and it is presented by The Natural Sapphire Company with full disclosure of enhancement and origin. Heat treatment is standard for Ceylon sapphires and in this case it has been applied to stabilize and intensify hue without compromising clarity or structural integrity. The very very slightly included clarity grade at eye level means inclusions are minor, often localized, and do not interfere with secure bezel or prong settings. Practical considerations for mounting include allowing for the slightly above average table and moderate depth geometry, which will sit well in both open gallery and closed back designs depending on desired light interaction. For connoisseurs considering appraisal or bespoke jewelry design, we recommend laboratory grading for documentation, and our team can advise on settings that maximize face up color and security. The combination of Ceylon origin, intense yellow saturation, mixed brilliant cutting, and excellent polish make this 1.61 carat round sapphire a technically interesting and visually compelling choice for collectors and designers alike.